1. Field of the Invention
Embodiments of the invention relate to a permanently or temporarily implantable device having an elongated electric conductor.
2. Description of the Related Art
Devices of this type, for example, electrode lines for electrostimulation, have the disadvantage that the electric conductor thereof can heat up in an MRI scanner because the alternating magnetic fields prevailing in the MRI scanner induce not inconsiderable electric currents in the electric conductor. For this reason, nowadays patients with cardiac pace makers usually cannot be examined, or can be examined only to a limited extent, in an MRI scanner.
At least one stimulation electrode line is typically connected to implantable cardiac pace makers or defibrillators, which stimulation electrode line has a standardized electrical connection at its proximal end provided for connection to the cardiac pacemaker or defibrillator and has one or more electrode poles on its distal end provided for placement in the heart. An electrode pole of this type is used to deliver electrical pulses to the tissue (myocardium) of the heart or to sense electric fields in order to be able to sense an activity of the heart within the scope of the so-called sensing. Electrode poles are typically provided in the form of a ring around the electrode line with an electrically conducting surface or in the form of a point electrode or tip electrode at the distal end of the electrode line. The electrode poles are connected in an electrically conducting manner via one or more electric lines to contacts of the electrical connection of the electrode to contacts of the electric connection of the electrode line at the proximal end thereof. Thus one or more electric lines run between the contacts of the electrical connection the electrode lines at the proximal end thereof and the electrode poles at the distal end of the electrode lead, which electric lines electrically connect one or more of the electrode poles to one or more of the contacts. These electric lines can be used on the one hand to transmit stimulation pulses to the electrode poles or for transmitting electric signals recorded by means of the electrode poles to the proximal end of the electrode line and are referred to in the course of the further description as a function line. Function lines of this type are electric conductors necessary for the functions of the respective electrode line and as such are exposed to the risk of electric currents being induced in them through external alternating magnetic fields, which can lead, for example, to an undesirable heating up of the function lines or of the electrode poles connected to them.